While looking for an image to illustrate this post, I ran across the one I’ve inserted here.

The data is from the NHANES, the U.S. National Health and Nutrition Examination Survey, a continuous program of studies designed to assess the health and nutritional status of a nationally representative sample of children and adults in the United States. Graphed is the distribution of BMI across the population, according to the NHANES, and how it has shifted over the past 30+ years.

I wanted to use this graphic to illustrate something — the distribution of weight in the 1976-1980 period, as represented in this graph, shows at least 50% of the population having a BMI of greater than 25, that is, in the “overweight” category or higher.

The dashed line graph, showing NHANES data from 2005-2006, shows approximately 2/3 of the population with a BMI greater than 25, which is what we’ve been hearing — that one out of every three adults in the U.S. is overweight or obese.

But, back to the 1976-1980 period, with one in two adults with a BMI greater than 25 — and the graph is of a “normal” distribution, a lovely bell-shaped curve, with a longer tail to the right than the left. This population distribution is one that would be expected in a population measure like BMI. The 2005-2006 distribution is flatter — more people distributed further to the right, and a longer tail.

It is hard, or really, impossible, to know who, living today, may have had a lower BMI were they the same age in 1976-80, and who is has the same BMI that they might have had then. It appears as though everyone has gotten fatter, but that isn’t the case — some people have gotten fatter, some have stayed the same — all but perhaps 1 out of every 4-5 people is still in the same pattern as was seen in 1976. (Anyone want to use some advanced algebra skills to determine the differences between the curves?)

If the way the problem is perceived is that no one should have a BMI greater than 25, then one half of the population in 1976-80 was “out of line” — how would one tell who is “naturally” in the BMI greater than 25 category, and who is “unnaturally fat?”

We can’t differentiate — we have no good way of knowing. We also don’t know when it comes to children.

I suppose I’m thinking about other differences, such as the distribution of height. Over the past century, we have gotten taller as a population, but in my family we haven’t gotten much taller than 5 feet or so. Are we abnormally short — pathologically short? The primary impacts of being shorter than average are those imposed by society, not a direct result of height itself. Or, if a child is born and develops into a very tall child, is that child’s height pathological? Are they to sleep standing up with bricks on their heads? Are they to be limited in the quality and quantity of food so they don’t reach their full potential in terms of height?

If the problem isn’t fatness per se — as many of us don’t believe that fatness is the problem — then what is? I don’t think it’s true that there isn’t a problem that is leading to those shifts in the population. I don’t think that fatness is the main negative outcome of the problem. Some of the people, perhaps as many as 1 in 5, being fatter than they otherwise might be isn’t the main issue.

In my humble opinion, I think the problem is quite fundamental, and it has an impact on people across the BMI spectrum. I would say that the main problem is that there are more calories produced for consumption in the U.S. than can be consumed without creating health problems — and that there is a tremendous amount of advertising poured into our lives to encourage us to consume those calories. Fatness itself isn’t the health problem — the health problems that result from our food system impact people of all sizes. It’s not processed foods, or even food. It’s too much being marketed to us, it’s a consumer-based economy, it’s the push to somehow consume constantly what’s being pushed at us and then being blamed for our woes, be they health or over-extended credit or feeling “less than” for not participating in the whole consumer-driven culture.

I alone can’t say what the problem is. I only can feel one part of the proverbial elephant. The important thing is that those of us affected by the problem are the ones to define it. Diagnose it. There is nearly consensus on what the problem is by people who aren’t fat. It’s up to us to lead the way to an accurate diagnosis, or at least highlighting when the diagnosis is wrong.

Treating the wrong problem isn’t benign. It’s harmful. It violates the ethical law of “first do no harm.” We have seen time and again when people have been blamed for their own “sickness” — only to discover a shift in understanding that the person was never sick to begin with.

I am probably not quite saying what I am trying to here. I blame daylight savings time.

3 responses to “Wrong diagnosis = wrong, harmful treatment”

The second graph shows more extremes in the population appearing – it’s not just that more people are sitting beyond the magic 25, it’s also that the tail is pushing into more extreme territory. It’s interesting to compare that to graphs of calorie changes over time that have been constructed, the latest being Stephan Guyenet’s look at the increase of sugar: http://wholehealthsource.blogspot.com/2012/02/by-2606-us-diet-will-be-100-percent.html

Also, people tend to gain some weight as they age. Since we have the aging demographic of us baby boomers, what effect would that have on the above graph. It would be very interesting to see the above graph at age 30 only, to see if it has the same pattern.